1. Field of the Invention
This invention relates to novel 4-halopyridine-3-carboxamide compounds and herbicidal composition thereof.
2. Description of the Prior Arts
Certain 4-halopyridine compounds 4-halopyridinecarboxamide are disclosed in the literature.
That is, German Laid-open Patent Application No. 2417216 discloses 4-chloro-N-phenyl-3-pyridinecarboxamide hydrochloride as a bactericidal agent. Bala, Marian et al. (Chem. Abst., 88, 6686s) reported 4-chloro-N, 2-diphenyl-3-quinolinecarboxamide, 4-chloro-N-methyl-N, 2-diphenyl-3-quinolinecarboxamide, 4-chloro-N-(4-methylphenyl)-2-phenyl-3-quinolinecarboxamide, 4-chloro-N-(4-methoxyphenyl)-2-phenyl-3-quinolinecarboxamide and 4-chloro-N-(4-N',N'-dimethylaminophenyl)-2-phenyl-3-quinolinecarboxamide which were prepared by the reaction of quinoline-3-carbonylchloride compounds with amines, and each structure was confirmed with an ultraviolet and an infrared spectrum thereof. 4-Chloro-N, 2-diphenyl-3-quinolinecarboxamide was also obtained by a method similar to that disclosed by Bala, Marian et al. (Zankowska-Jasinsca, Wanda et al, Chem. Abst., 83, 58620 g). Nagano (Chem. Abst., 55, 11413 g) reported the preparation of 4-chloro-N-phenyl-3-quinolinecarboxamide, 4-chloro-N-(4-ethoxyphenyl)-3-quinolinecarboxamide and 4-chloro-N-(4-methoxyphenyl)-3-quinolinecarboxamide by treating the corresponding 4-hydroxy compounds with phosphorus oxychloride. U.S. Pat. No. 4,312,870 and European Patent Application No. 168350 described 4-chloro-N-(4-chlorophenyl)-3-quinolinecarboxamide and 4-chloro-N-(4-chlorophenyl)-5,6,7,8-tetrahydro-3-quinolinecarboxamide as the raw materials for pyrazoloquinoline compounds having attractic activity. Japanese Unexamined Patent Publication Nos. 59(1984)-112967, 58(1983)-29764 and 57(1982)-53462 disclosed certain 3-carbamoylpyridine derivatives possessing herbicidal effect. However, all the compounds disclosed in the above mentioned 59(1984)-112967 and 58(1983)-29764 publications have an N-benzylcarbamoyl group at the 3rd position of the pyridine ring, while those disclosed in the above mentioned 57(1982)-53462 publications are N-phenyl-3-pyridinecarboxamide derivatives in which however the 4th position of the pyridine ring is a hydrogen atom and the 5th position is substituted by cyano, carboxyl or a lower alkoxycarbonyl. Therefore, the compounds disclosed in the above mentioned three Japanese patent publications are structurally different from the compounds of the formula (I) as mentioned below.
As discussed above, there were no reports on the 4-halopyridine-3-carboxamide compounds of formula (I), nor any suggestion on their herbicidal activities.